Field of the Invention
The present invention relates to a multilayer wiring board and its manufacturing method.
Description of Background Art
JP2013-214578A describes a multilayer wiring board structured which has a main wiring board formed by alternately laminating conductive patterns and insulation layers and a sub wiring board (wiring structure body) formed separately from the main wiring board. To obtain a multilayer wiring board where mounting pads and conductive patterns are formed at a narrow pitch, the wiring structure body is prepared separately to have narrow-pitch conductive pads and conductive patterns, and then embedded into the main wiring board. The entire contents of this publication are incorporated herein by reference.